The tool worked 85 percent of the time in tests and is being refined before commercialization or licensing, says Alina Oprea, a research scientist at RSA Labs, who cowrote the software. “The tenant can run this protocol without the help of the cloud provider. This would give them stronger guarantees,” she says. Similar approaches under development could monitor other shared hardware elements, such as hard drives, she adds.

Companies also want to ensure that their remotely stored information won’t be corrupted, lost, or stolen. Encrypting data before storing it can help, but this requires keeping track of encryption keys and monitoring new technologies for their potential to break the encryption. (On the plus side, a future system might allow you to actually compute with encrypted data, infeasible with current technology.)

These downsides of encryption can be avoided with a newly commercialized technology that provides a mathematical way of slicing your data into 16 parts before storing it. It employs a fancier version of algebraic equations (in which knowing two parts of an equation lets you solve for the third) to let you reconstitute your full data set from any 10 of those 16 slices.

This process does increase the amount of data you need to store by between 30 percent and 60 percent, but that’s more efficient than some encryption methods. And if you distribute your 16 slices among different storage providers, “you can build systems where you don’t have to trust the service providers,” says Chris Gladwin, CEO of Cleversafe, the Chicago company that launched the software late last year. “They can tamper, lose, or steal it and it doesn’t matter if they steal below a threshold.”

Other technologies are in the works to make cloud computing more secure, because no one doubts that as data moves to clouds, so will hackers and criminals. “Anyone can use Amazon,” Ristenpart says, “so criminals have access to it as well.”